Rewarding fat rats

Feb 16, 2007

We all remember a time when we were paralyzed in the face of a tough decision. For animals in the natural world, making the right choice can mean the difference between life and death.

When rats and other animals choose the thing that leads to a "reward," such as food, changes happen in the body and the brain. Describing and understanding those changes has been the focus of Natural Sciences and Engineering Research Council grantee Peter Shizgal for most of his career.

Shizgal was recently recognized for his contributions by the American Association for the Advancement of Science. He will be inducted as a fellow during its annual conference in San Francisco.

"It's an honour to receive this sort of recognition from one's peers, and I do feel proud," says Shizgal, a Concordia University professor of psychology. "That pride should be shared. Achievements like this in the natural sciences often reflect the work of a team, and that is certainly true in my case. I have been privileged to have terrific trainees and faculty colleagues as research collaborators, many of whom have been supported by NSERC scholarships and grants."

In their studies of food reward, Shizgal's team investigated the role of leptin, a hormone that the body produces in proportion to the amount of stored fat. A person who eats a lot during holidays, for example, will make more leptin than a person who sticks to a stricter diet.

In work carried out by Shizgal's team, chubby lab rats were put on a diet to reduce their fat mass and, hence, their leptin levels. They found that restricting the rats' diet to one meal per day not only made them lose weight, but also made reward sensations stronger. Conversely, increasing the level of leptin in the brain weakened the reward sensation. Their work has appeared in notable journals such as Science and Behavioral Neuroscience.

"Trying to understand the brain mechanisms of motivation in animals – and also in humans – is not only fascinating for me, but also highly rewarding. More broadly, there is an exciting confluence of work emerging from both major branches of NSERC-supported research: natural science and engineering," says Shizgal.

"While natural scientists use concepts and technologies developed by engineers to try to understand what makes animals tick, certain computer scientists and engineers look to the natural world for inspiration and guidance as they build intelligent machines. Ongoing research has already produced some computer programs and robots that can learn from experience and adapt their behaviour to a complex, constantly changing environment. We can expect that this technology will be greatly improved in the near future."

Source: Natural Sciences and Engineering Research Council

Explore further: Warning coloration paved the way for louder, more complex calls in certain species of poisonous frogs

add to favorites email to friend print save as pdf

Related Stories

MasterCard, Zwipe announce fingerprint-sensor card

18 hours ago

On Friday, MasterCard and Oslo, Norway-based Zwipe announced the launch of a contactless payment card featuring an integrated fingerprint sensor. Say goodbye to PINs. This card, they said, is the world's ...

Plastic nanoparticles also harm freshwater organisms

20 hours ago

Organisms can be negatively affected by plastic nanoparticles, not just in the seas and oceans but in freshwater bodies too. These particles slow the growth of algae, cause deformities in water fleas and impede communication ...

Atomic trigger shatters mystery of how glass deforms

20 hours ago

Throw a rock through a window made of silica glass, and the brittle, insulating oxide pane shatters. But whack a golf ball with a club made of metallic glass—a resilient conductor that looks like metal—and the glass not ...

Recommended for you

Cat dentals fill you with dread?

20 hours ago

A survey published this year found that over 50% of final year veterinary students in the UK do not feel confident either in discussing orodental problems with clients or in performing a detailed examination of the oral cavity ...

User comments : 0